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mhotze

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Everything posted by mhotze

  1. I recently switched to Cura 2.7, and am glad to see the continuous improvement of the software with regard to how it is handling dual extrusion setup. Thanks for that effort! An idea to further improve is the less intuitive (and hence error-prone) handling of temperature profiles. As I more or less tried to deduce, I think the actual temperature used is a combination of settings: Print Core & Material + Profile + Default settings These are all stored for both cores in a single setting file. So in the end this is quite cumbersome when changing material, changing cores, use settings of one profile from core 1 in core 2, or in general where to change temperature settings in the first place (e.g. Print Core & Material or Profile). My idea is to handle materials differently: - merge Print Core & Material settings with Profile settings --> make one settings profile - store these settings per core I wonder if that would simplify and improve Cura further or is this an over-simplification?
  2. Ah, so I guess replacement screws which are longer than the original screws that are already there? Again, very nice! Easier to mount as well compared to my design. Would you be willing to share your design?
  3. I've recently printed a very large and flat ABS part, see picture below using the winning adhesion method (see my previous post with the link): I was actually surprised to see there was no warping at all, the model stuck very well to the heat bed. After it popped off when the build plate cooled down, the model was even bending upward in the center a millimetre or so, so weirdly enough, it had some kind of inverse warping. No clue as to why this happened.
  4. That looks cool!! I wonder how the hinges are helt in their position. Looks like sort of a clamping mechanism? Does that work well enough to keep them in position?
  5. Could not find this in release notes of 2.5. Is it in?
  6. I agree. I will discuss this with "the powers that be" Oohoops. For me a lesson to have a look at the release notes before upgrading. Well... I wonder if I would have noticed. It's this line I think, in retrospect right? "Initial layer printing temperature. The initial and final printing temperature settings have been fine-tuned for higher quality results." I also just found out about the +5deg change when going to Cura 2.4. I noticed considerable oozing after the first prime poop going to the brim, which I did not recall seeing before. I first thought it to be a setting issue. Double checked everything, finally had a look at the g-code, and noticed the +5 deg. Took me a day or so to figure out.
  7. Cool! Now let's see if some hybrid of the 3 designs will pop-up Update here from my door: it's still a pleasure to work with, I did not have to adjust the prime positions or anything.
  8. I'm aware of that and all effort on Cura appreciated. I'm tempted to help, a bit off-topic, but I wonder if Cura is 100% a community effort. I think it's hugely promoted by Ultimaker, it came with my UM3, which a paid >>3k for. I think that's the underlying reason for some frustration, but I'm open to help as well. Does Ultimaker hire on project basis ?
  9. Just upgraded to 2.4 yesterday, and noticed this issue right away. Thanks for the workaround.
  10. I tend to believe warping is mainly an adhesion problem, and to lesser degree a settings issue. I've compared bed adhesion methods (here) and went for the best solution, all prints came out fine since (read for about a week since my test). For both ABS and PLA. What do you use for adhesion? Bare Glass?
  11. "Maximum Fan Speed The Speed at which the fans spin on the minimum layer time. The fan speed gradually increases between the regular fan speed and the maximum fan speed when the treshold is hit." What? Reading. Reading again. And again. Does not help much. What is Cura trying to tell me? Fans spinning on minimum layer time? Fans spin on electricity. And I guess until minimum layer time, fans spin at regular speed? Which treshold? And probably the fans go from regular to max after the treshold is reached, not at the instant some threshold is hit, and still there's something of a gradual increase, some contradiction there. Hmm. How gradual? Damn... Above rewritten: Maximum Fan Speed This setting defines the maximum fan speed. When the "Regular/Maximum fan Speed Treshold" is reached, the fan gradually increases between regular fan speed and maximum fan speed. ...and that's just an example.
  12. ...or to better understand the way to get a grip on your settings. For me also to gain some more understanding (please give feedback with more info!) and suggest improvements. I seem to have lost some carefully tuned settings and I could not get my head around the way Cura handles settings. So here's an attempt to get things clarified. At least, up until the moment some ambiguity in how settings are used is solved and things are self-explanatory. One of the ambiguous things currently is for instance that temperature profiles can be stored both in Material settings and User Profiles. Some of these in return influence other parameters which makes it quite tricky to setup your print and making you wonder what happens with your settings you thought you defined earlier. So here we go. I'm on OsX (mac), and talking Cura 2.4 now with a UM3. I guess the OS does not matter that much, but the way Cura handles profiles and settings can be more subject to change depending on the version you're using. How to figure out how settings are used in Cura One way to approach understanding the way Cura works with settings, is to have a look what is going on "under the hood". Well, yes, not that I wanted to, but that's where I ended up. To be honost, euh, also had a peek at the competitor to check how they are doing, and if that's worth the investment instead of putting time and effort in Cura. But anyways, back to settings in Cura. It looks like there are default settings, which are stored in setting files, and user settings that overwrite the default ones. All are human-readable ascii files which make it possible to see at least what is stored. With changing Cura versions and the way settings are handled, this kind of exercise can be useful to master in that sense, in order to figure out yourself how things work with future releases. So how are settings used? There are multiple setting files that influence the final settings that are used: The Default Settings: Cura has default settings, which depend on the printer used. I think the default settings are stored in the application directory: Applications/Cura.app/Contents/Resources/resources/definitions. In my case, the settings are stored in the file ultimaker3.def.json. Superimposed on this, are the standard or user defined material settings. The important settings stored are Default Printing Temperature, Build Plate Temperature, Retraction speed and Distance, Standby Temperature and Fan Speed. Now the tricky thing I've seen by now are twofold. 1) Some of these parameters influence settings like printing speeds from the default settings, at least if they are not stored explicitly in a user profile. 2) Some of the material settings can also be stored in user defined profiles. It seems to be undefined behaviour which settings are actually used in those cases to calculate settings like for instance the printing speeds. I'm not sure of if this is intended or not. Getting this ambiguity solved would be beneficial. There are also Standard or User Profiles. Since we're talking about finetuning settings, I'm skipping directly to User Defined Profiles. For OsX, they are located in your_home_folder/Library/Application Support/cura/quality. In case of a dual extrusion printer, the settings are stored in 3 different files. These are the settings which are extruder independent (the Global settings if you have a look at the Profile Manager in Cura), and for each extruder individually. The way it currently seems to work, is as if there are changes to either settings defined by the default printer settings or material settings, these are regarded as "updated", and can then be stored in the current user profile by clicking "update profile with current settings/overrides". Only these "overridden" settings are then stored in a user profile. At least, I think that's the way it's working. Let me know if there's things incorrect or missing so I can update the story above if needed. Also, for non- OsX users, it could be beneficial to inform which directories are used, for other users to have a peak to their actual settings files. The way I'm currently working is examining how my settings are stored and take some notes in a text file, and double check if the relevant parameters turn up in Cura, especially when changing filement and reverting back to settings used earlier. Note, that I've not yet found a way to delete settings in a profile (for instance to delete retraction amount in a custom profile, in order to only define them in the material profile), other than delete settings using a text editor. This helps both in de-cluttering settings and knowing what you're doing (which I hope would be solved in a future release, next of course in solving the ambiguity issue explained above). One solution could be to visualize what are default settings and what are overrides by user profiles, and what are overrides by material settings (or even ditch material settings completely and go for user profiles only).
  13. Bump... thanks for pointing me from this post to this one, I now see with dual extrusion a collision happening when the second prime position is travelled to, the print head quite violently hits the prime poop already there. So now I wanted to have a look at changing the prime position, but I'm faced with this message: I think I need to change some setting, but as of now clueless where to change it.
  14. That would be very interesting, a contest between adhesive sheets, kapton, and ABS juice or 3d Lac. If someone is willing to test that... or send me some samples in generous quantity
  15. For the adventurous (use at own risk), here it is: http://catch22.eu/3dprinting/u3door/ Detailed instructions: here are some I could think of right now. Tricky part is finding the correct position to drill holes in the door itself (not too low, otherwise the extruder hits the clamps). There needs to be about 5mm play in z-direction between bottom clamps and top clamps, although the latches have slotted holes which aids well enough in drill hole accuracy I think. Best way to find the positions is to drill at least holes for the bottom and mount the bottom clamp, then find the correct position for the top clamps. The top clamps have sort of a centering mechanism, so both X and Z positions for the holes do matter. My suggestion for door material is to take something that can withstand some temperatures (mine is from 4mm polysterene, which can handle 75C, although I'd rather go a bit thicker than 4mm to give it some more rigidity). The clamps are made for M4 size screws, and ABS of course. Take also care for the remarks below/above using maximum possible build volume. Please let me know if the stl files are correct (I had to edit them for general usage by giving them the correct orientation).
  16. Ah, ok, that's what you mean. Yes, for my system as well it's possible to move the print head further than the default prime position. Does this mean that it's possible with default settings to protrude the door, or are custom settings needed in order to hit it? [edit: I see ultiajan already answered this question]
  17. Nope, I've checked today, there's about 5mm clearance.
  18. That's sharp! I've measured temperatures along the test (see my site here as well: http://catch22.eu/3dprinting/adhesion/), and what a coincidence, 66 temperature peaks coinciding with 66 layers and the top and bottom walls being 4 layers. The 4 blocks were printed clockwise in my case. The sensor on the print head is placed about 10mm height from the build plate. And I do use a door, but apparently, this still causes a temperature gradient. So you know what causes this? My door has slight draft (not sealing 100%), and the backside holes are sealed with ducktape (as can be seen on the picture). Is there still some draft I wonder (slightly off-topic though).
  19. And the winner is....well... results published here (easier to edit and handle the pictures): http://catch22.eu/3dprinting/adhesion/ (it's 3D Lac) My site does not handle comments, please post here on Ultimaker Forum. Hope this sheds some lights on how well these methods compare (at least based on this single data point, and do note that these results might be different when printing for instance with PLA instead of ABS). So it could be beneficial if similar tests are shared as well!
  20. Ok, thanks, so this looks like 2 votes at least for wood glue. I see a Elmer's being mentioned quite a lot indeed, though Bison is the glue Brand here in NL, so have to go for that brand I think. First result of only using 3D Lac were impressive by the way (with PLA filament). I even had difficulty releasing the print from the bed after cooling down. Not sure yet if this is the same as the suggestion given to use hairspray for the test. Maybe too cautiously applied by myself, or the wrong brand (Andrelon Ultra Hold Fantastic Hairspray), I did not fare well yet trying that. Any other suggestions still welcome until I've found time to do the test. Otherwise it will be wood glue - let me know!
  21. Thanks for your replies. Are you sure the door is hit? It looks like it's on the edge of hitting it, but did not notice it so far... I checked when designing the door, but to be honest, I also take out the door to catch the pre-priming dropping to prevent it from being dragged to the print area. Otherwise, I'd opt to give Ultimaker at least a suggestion to adjust the priming position. Is that prime position hard-coded in firmware??? It's quite silly otherwise to have the head stick out per default that much during the priming. The design is available in Onshape publicly, but since there's debate on the safety of this design, I'd not post a direct link yet (otherwise PM me).
  22. Since there's no official solution yet from Ultimaker, here's my solution for an UM 3 door I'd like to share. It is opened / closed by lifting ~5mm and pulling the bottom handle. The top handles have a grabbing mechanism and centers the door: Attention: the top handle / clamping mechanism needs to be sized and adjusted well, to prevent collision with the print head.
  23. An idea popped up to get a better, more objective comparison of different build plate adhesion solutions for ABS. The idea is simple: divide the build plate into four equal segments, and apply build plate adhesion solutions (glue, hairspray, juice and the like), and print four 3D objects on these segments. It's probably important to have the four segments on equal distance from the centre of the build plate, to rule out any non-uniform temperature. The results of the four prints can be quantitatively compared by measuring warping, but also qualitatively by visual comparison. So here's an opportunity for input for all, because I've a free slot available on the fourth segment. - Which build plate adhesion solution would you vote for to test? - Which one do you bet on will be the best one? - Or, feel free to copy this test and share your results (for instance comparison between Kapton, PEI, blue painters tape, etc).
  24. So after checking various sites, here's some things I've found as well regarding warping. It does point into a shear force issue. There’s however quite some differences in the build plate temperature set-point and motivation for it to combat warping: Reduce warping by reducing the temperature difference between extrusion temperature and build plate: https://ultimaker.com/en/resources/158-print-not-sticking-to-build-plate Set build plate temperature to the heat deflection temperature (HDT): https://bootsindustries.com/heat-bed-3d-printing/ Go for the glass transition temperature: https://ultimaker.com/en/resources/19537-how-to-fix-warping Interestingly, this site also mentions not to go too high with HBP temperature (at least for PLA): https://rigid.ink/blogs/news/3d-prints-warping-why-it-happens-and-how-to-prevent-it Looking at my earlier prints, I tend to go for a too high heated build plate at first, as these show some inward deformation of the first layers: Train of thought goes like this: the first few layers are kept above HDT, which causes a shearing force with each successive layer. With adequate build plate adhesion, this results in successive shrinkage of each layer added, but also the layers already deposited, as they are kept above HDT. Warping did not really change by going from 99C to 85C, but the effect of inward shrinkage of the first few layers up until say 10mm did. Note that all points into the direction of a shear force related phenomenon. The above also suggest there's an optimum HBP temperature to look for: not too high (causing inward deformation of the first few layers) not too low (causing too much cooling and going too much below HDT) At least that’s what I found, but a might be wrong still there. I wonder if there’s support for this by observations from others? Other measures to reduce warping (I think in order of importance): getting as best as possible adhesion to the build plate, reduce shear forces by setting lower infill, smaller bottom thickness, smaller wall thickness, prevent sharp corners, going as low as possible with the extrusion temperature to reduce temperature drop and related shrinkage. For the curling thing at the top, I have not looked that well yet as what happens here exactly. It seems less of a inter-layer shear force phenomenon compared to warping?
  25. Idea: have stepper motor vents at backside plane instead of vent holes inside the chamber. This gives more thermal headroom for the stepper motors when mounting a front door (or even further enclosing the chamber). By the way, I measured so far motor temperatures below 60C in all scenarios so far, but not going to extremes either.
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